The present invention relates to a glazing, especially for windows and French windows, of the type consisting of two panes located opposite one another and retained by means of a rigid frame provided with leakproofing means.
More specifically, the invention relates to a glazing of the type indicated, which is provided with a deformable and leakproof member for equalizing pressure between the outside and the inside, this word designating, here, the space contained between the two panes.
The pressure variations between the outside and inside of a double glazing can be attributed to meteorological phenomena or to heating of the gas contained inside under the effect of the sun. To prevent them from causing damage, it is customary to give the panes sufficient thickness and embed them firmly in the frame. It should be noted that the larger the glazing, the more the frame is subjected to stress: if the dimensions of a square glazing are doubled, the forces attributed to the differences in pressure are quadrupled, whilst the length of the frame is merely doubled.
There has been a proposal (U.S. Pat. No. 2,207,745) to equalize the pressures by means of holes provided, if aporopriate, with filters, but this solution is not entirely effective in eliminating the condensation arising from moisture inside the glazing.
There has also been a proposal (DE-A No. 2,730,119) to place between the panes and the frame an element made of deformable material, such as rubber. This element constitutes the leakproofing means anchoring the panes to the frame, and between the panes it forms a flexible diaphragm, one face of which is in contact with the outside air and the other face in contact with the inside of the glazing and which is deformed under the effect of the relative pressure variations. The disadvantage of this solution is that it gives rise to forces exerted on the part of the element forming the leakproofing means, with the attendant risks of fatigue or displacement.
The document U.S. Pat. No. 4,065,894 describes a glazing, the frame of which, preferably made of wood, contains in its thickness a receptacle which communicates with the outside via a duct.
Located within this receptacle is a bladder or vessel made of flexible material, the interior of which is connected to the inside of the glazing by means of a tube. This tube passes through a gasket made of elastomeric material, which serves both to provide leakproofing between the frame and the inside of the glazing and to prevent the panes from moving closer to one another. The frame has a groove in which the edges of the panes and the elastomer gasket are accommodated, the edges of this groove preventing the panes from moving apart.
This device makes it possible to achieve effective equalization of the pressures inside and outside, but it makes it necessary to provide a bulky frame. In fact, on the one hand, the frame must be large enough to contain the cavity in which the bladder is located, and this cavity must allow variations in volume of the bladder; these variations in volume increase if the distance between the panes increases. On the other hand, since the panes are retained by means of a groove, the frame necessarily has a width greater than the distance between the outer faces of the panes. For these two reasons, it becomes necessary to limit the distance between the panes, but this reduces the heat-insulation qualities of the glazing.
There has, moreover, been a proposal for arrangements in which the panes of a glazing are bonded to a "spacer" section located between them (FR-A No. 1,433,252), the glazing being without any pressure-equalizing member. It seems possible, by using this technique, to reduce the forces exerted on the frame which are attributed to internal excess pressure and therefore to reduce its thickness, but there has never been a proposal to locate such glazing other than within grooves provided within the frame. This system would therefore make it possible, in theory, to increase the distance between the panes for a given thickness of the frame, but the latter nevertheless still has a thickness greater than the distance between the outer faces of the panes. On the other hand, this system scarcely makes the process of obtaining and installing the glazing any simpler.
Furthermore, it is conventional to fasten to the frames various accessories enabling the glazing to interact with a fixed surround, for example hinges, bearings, leakproofing means and lock components. This has been done for a very long time with wooden frames and single panes, and the technique has simply been modernized for glazing with multiple planes and metallic or like frames, having a shape which allows various accessories to be attached.
The end result of this is a costly construction, because it involves several stages, some carried out at the factory and others on site.
The object of the invention is to provide a glazing which, at the same time, has a higher quality than those of the prior art in terms of its heat-insulation properties, because of an increased distance between the panes, and is simpler to obtain and has a reduced cost price.
The object of the invention is also to provide a simple process for obtaining such a glazing.